In 2020, Swiss dive watch specialist Aquastar was relaunched with the simultaneous return of a slightly larger version of the Deepstar chronograph from the ‘60s (see February 2021 issue). Since November 2021, the brand’s first three-hand watch is offering a much more affordable option for those who missed out on the chronograph, or didn’t want to spend $3,590 on one of the four dial options (which were all sold out rather quickly).

Interestingly, Aquastar chose to not relaunch another of its classic designs (which is bad news for all those who had hoped for a return of the Benthos), but instead opted for a declination of the Deepstar’s design. The Deepstar II, like its 40.5-mm chronograph counterpart, comes with the large silver subdial, this time at 9 o’clock (instead of 3 o’clock) for the permanent second hand (instead of the minute chronograph counter). The satin-finished case, however, measures 37 mm (around 47 mm lug to lug) and is based on the design of the first dive watches from the brand, and therefore offers a very compact alternative.

Like the Deepstar Chronograph, the Deepstar II comes with a 200-meter water resistance, but is powered by a top-grade Swiss-made automatic movement from Sellita (SW290-1 with 38-hour power reserve). As a result, the Deepstar II is priced at $1,490 during the brand’s preorder period. The stainless-steel beads-of-rice bracelet is sold separately, but a Tropic and Horween leather strap are included. The polished, bidirectional bezel is mounted with ceramic bearings and features the brand’s typical decompression engravings for calculating repeated “no decompression” dives. While the bezel pip, hour and minute hand as well as the hour indexes are covered with high-density “old radium”-style Super-LumiNova, the second hand unfortunately remains invisible at night.

The Aquastar Deepstar II is currently available in three dial options: “Steel Grey” (pictured here), “Vintage Black” and “Blue Ray,” with each being limited to “an opening series” of 300 individually numbered pieces, which sounds like there might be an option for the brand to add more pieces and colors, in case demand is bigger than supply.

Surprisingly, the 37-mm watch wears bigger on the wrist than one might assume, which is mostly because of the 47-mm lug-to-lug length. The biggest surprise, however, is that Aquastar has managed to create a completely new model that looks like it has been part of the brand’s collection for almost exactly 60 years.

Aquastar Deepstar II Specs

Manufacturer: Montres Aquastar GmbH, Leugenestrasse 6, 2504 Biel/Bienne, Switzerland 

Functions: Hours, minutes and seconds (9 o’clock) 

Movement: Sellita SW290-1, automatic winding, 28,800 vph, 31 rubies, 38-hour power reserve, diameter = 25.60 mm, height = 5.60 mm 

Case: Stainless steel, screw-in crown and caseback, domed sapphire crystal, water resistant to 200 m, bidirectional ratcheting bezel (120 clicks) with decompression time calculator 

Strap and clasp: Tropic rubber strap with signed buckle 

Dimensions: Diameter = 37 mm, height = 14.80 mm, lug width = 19 mm 

Variations: With blue or black dial (each limited to 300 pieces) 

Warranty: 1 year 

Price: $1,890

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For many collectors, the history of the dive watch starts in 1953 with the introduction of the Blancpain Fifty Fathoms and Rolex Submariner. Divers, however, already had to rely on water-resistant watches, decades before the commercialization of two of the category’s most iconic models. We take a deep dive into how the history of underwater exploration and the evolution of the wristwatch are connected.

In 1942, German trade publication Uhrmacher-Woche (Watchmaker’s Week) began an extensive article about water-resistant watches with the following opening paragraph: “15 years ago, when the water resistant watch hit the market, many expected it to be an advertising gimmick or a fashion fad, because it isn’t really necessary to wear a watch when swimming.” The author then quickly went on to conclude that “the development of the air-tight watch became a technical necessity and important for the outcome of the war, because in rooms with lead storage batteries, in factories, on board submarines the air is filled with acid fumes.”

From the Pocket to the Wrist and Into the Waters of WWII 

What makes this article from 80 years ago remarkable is the combination of several misconceptions about the development of the waterproof or water-resistant wristwatch that ultimately culminated in the invention of the dive watch. First, Rolex clearly did manage to create an impact “15 years ago” by placing its famous full-page advertisement on the front of London’s Daily Mail on Nov. 24, 1927, proclaiming the success of the first waterproof wristwatch and chronicling “the debut of the Rolex Oyster and its triumphant march worldwide” after then-26-year-old British professional swimmer Mercedes Gleitze swam the English Channel wearing a Rolex Oyster, thus spending more than 10 hours in the chilly waters between France and Great Britain. Second, not a single word mentions divers or diving, even though helmet diving had already become an established industry by then. Other fields of application seemed much more important than diving or “swimming,” which ironically was also the case with many of the innovations that helped establish diving itself. It was, for example, the idea for a smoke helmet by Charles Deane in 1823 that led to the development of the first successful diving helmet (which consequently resulted in Augustus Siebe, an engineer and former watchmaker, working on a helmet fitted to a full length watertight canvas diving suit in 1830). The same was true of the oxygen rebreather, which was as much intended to be an emergency escape apparatus for submarine crews, mine workers or firefighters, as it finally allowed helmet divers to work more independently without surface-supplied air via a diver’s umbilical.

Ironically, those early helmet divers came up with a rather pragmatic way to know how much time they had already spent underwater: the first dive watches were simply regular pocketwatches, mounted on the inside of a diving helmet. One reason for this solution: back then, the “bracelet watch” was “looked upon by Americans as more or less of a joke,” according to the New York Times from July 9, 1916. But, like the German Uhrmacher-Woche, the paper also concluded in the same article that “the telephone and signal service, which play important parts in modern warfare, have made the wearing of watches by soldiers obligatory.” Looking at those early field watches, wearing one underwater, over a thick dive suit and thus completely exposed to both water, pressure and potential bumps would have been much riskier (and more expensive) than simply mounting a pocket watch on the (hopefully) dry inside of a helmet.

Two years after the New York Times piece on trench watches, on June 11, 1918, New York based “manufacturers of high class specialties for Waltham watches” Jacques Depollier & Son was granted a patent in the U.S. for a “waterproof and dust-proof watch.” In an ad from the same year, Depollier also came to a similar conclusion as the New York Times. “With the general use of wrist watches for soldiers, sailors, aviators and others engaged in the open, the demand for waterproof watches has become much more insistent, and the fact that the demand still exists unsatisfied is an indication that a reliable waterproof watch has not until now been produced.” Depollier’s “D-D” field and marine watch was equipped with a double clinched bezel that promised to keep out “water, dust and gas.” Again, Depollier, like the New York Times, did not mention the diver as its intended target audience, even though their watch “might be completely submerged in water” and was advertised using a picture of it being placed in a fish bowl.

Rolex, on the other hand, brought out its first attempt at a waterproof and dustproof watch, the Submarine, in 1922. It turned out to be an impractical design, according to Rolex, since the watch was “relying on a second outer case to protect the main watch body. The outer shell had to be opened every day in order to wind the watch, thereby also weakening the metal gasket that sealed the opening.” Four years later, two major technical innovations of the company had made the single-case wristwatch watertight: a screw-down back and bezel, as well as a newly patented winding crown, which could be screwed down to seal the case. Rolex advertised the Oyster as the “wonder watch.” Mercedes Gleitze provided the proof (and also became the brand’s first testimonial).

Like Rolex before, Omega came up with a similar idea of a double-case construction for a watch that was targeted specially at “sportifs, marins et coloniaux” (athletes, sailors and soldiers). In 1932, the “élégante” Omega Marine utilized a patented case sealed with cork to “keep water and the elements away from the heart of the watch.” The rectangular watch even featured an adjustable clasp and was tested in Lake Geneva at a depth of 73 meters (later conducted laboratory tests found the watch to be waterproof to a depth of 135 meters).

A New Type of Watch, Robust Enough to be Worn Underwater 

In 1935, the paths of the watch industry and underwater operations finally became fully intertwined, when the director of G. Panerai e Figlio in Florence, Giuseppe Panerai, was approached by the Italian Navy to develop a water-resistant compass and a watch for operators of its newly developed manned torpedo. While Panerai had already been a supplier of special navy equipment, the company had never produced wristwatches. On Oct. 24, 1935, Rolex therefore sent Panerai a Ref. 2533 with a large 9k gold cushion case for tests, the very same watch that should later evolve into the Radiomir, used by Italian special forces (and later by the Germans after having seized some of these watches during the German occupation of Italy that lasted until May 2, 1945).

While members of the Decima Flottiglia MAS commando frogman unit were initially equipped with Panerai-supplied Rolex watches, the American Underwater Demolition Teams (UDT), predecessors of the U.S. Navy’s current SEAL teams, were equipped with “canteen watches” from the likes of Hamilton and Elgin (featuring a screw-on cover for the crown that was held in place with a small chain). Like the watches supplied by Panerai, these significantly smaller canteen watches were not equipped with a bezel, but simply indicated time with their luminous hands.

For the rotating bezel, clearly the visually most distinctive element on a dive watch, the watch industry first looked to the sky. On July 31, 1929, Philip Van Horn Weems applied for a patent for a “method of and apparatus for navigator’s time keeping” using a rotating bezel. The patent was granted in 1935 and soon found its way on to many pilots’ watches, the most important one being the legendary Weems watch from Longines. It would take a few more years until the watch industry began to recognize the potential for its diving customer. More precisely, with the rise of autonomous diving, based on open-circuit, compressed-air devices, like Yves Le Prieur’s invention from 1925, and, more importantly, Émile Gagnan’s and Jacques-Yves Cousteau’s regulator that was first patented in 1943 (and mass produced by La Spirotechnique after the war), the Self-Contained Underwater Breathing Apparatus (SCUBA) revolutionized diving, and consequently increased demand for a reliable underwater timing device.

Blancpain started in the early 1950s with the development and testing of the brand’s first wristwatch intended exclusively for divers. The Fifty Fathoms (a reference to the depth rating of 300 feet or 91.4 meters) was the brainchild of Jean-Jacques Fiechter, then CEO of Blancpain, who also happened to be an avid diver. In an interview conducted in 2018, Fiechter recalled that he was diving off the coast of France when he lost track of time and ended up running out of air, prompting an immediate ascent to the surface without stopping for decompression, and thus leaving him at the risk of the bends. His solution, and ultimately Blancpain’s “first modern dive watch,” was commercialized in 1953 and came with a new positioning for the caseback and crown gasket that would better protect the case and movement from water, resulting in a patent for both designs. More importantly, Fiechter had also introduced a unidirectional bezel with the Fifty Fathoms that would allow the watch’s wearer to better track how much time was spent submerged. In short, Blancpain had both improved the water-resistant case and added a bezel that was exclusively aimed at keeping track of time spent underwater.

Rolex, on the other hand, already had implemented a bezel on a watch with the Zerographe and was now working on the most waterresistant watch case of that time with an experimental watch, the Deep-Sea Special, which was attached to the exterior of Piccard’s Trieste during its first deep-sea trials down to 3,150 meters (10,245 feet) off the island of Ponza in 1953 (Jacques Piccard himself was seen wearing a Longines Chronograph 13ZN when diving outside the submarine). In 1960, Don Walsh, Jacques Piccard and another Rolex watch would reach the bottom of the Mariana Trench (10,916 meters, 35,814 feet). Almost simultaneous with testing the Deep-Sea Special, the company introduced the Submariner in 1953, a diving watch equipped with a rotating bezel. In 1954, the watch industry’s trade publication Europa Star first mentions the Submariner briefly as a watch that “has been specially designed for deep-sea diving,” and like the Rolex Turn-O-Graph, the Submariner “carries a Time Recorder bezel,” which “enables the consumption of air in independent diving equipment to be easily controlled.” According to Europa Star, the Submariner was “tested on 132 sea trials in the Mediterranean and declared a to be an essential accessory to diving equipment.”

While Blancpain and Rolex have defined the look and function of the modern dive watch, both had approached the problem from the same angle: a robust, highly water-resistant wristwatch equipped with a bezel that would be able to withstand external pressure. What they didn’t factor in: the rise of saturation diving, first in the military field, then in commercial application. Dr. George F. Bond, a U.S. Navy scientist, had introduced the concept of saturation diving in the late 1950s. Earlier experiments had shown that divers were able to live and work underwater for days or weeks at a time before making a single, comparatively short decompression period. Bond’s work is not only credited as the beginning of saturation diving, but also marked the start of the United States Navy’s Man-in-the-Sea Program. From 1964, a trio of saturation diving experiments that let divers work and live in undersea habitats (Sealab) was launched and supported by the United States Navy Experimental Diving Unit (NEDU). With the ill-fated Sealab III, the habitat was lowered to 610 feet (190 m) off San Clemente Island, California, on Feb. 15, 1969, a depth that would bring a standard-issue Submariner already near its limits. But it wasn’t just the depth that posed new challenges; helium caused the weakest part on some of the watches, the crystal, to pop off during decompression. And this wasn’t just happening to the divers in the Navy. In 1968, Japanese watchmaker Seiko received a letter from a saturation diver from Kure City, in Hiroshima prefecture. In that letter, the diver also complained that the dive watches from Seiko lost their crystals during decompression. While some divers simply unscrewed the crown before compression, Rolex wanted to offer a different solution for its 1967-introduced Sea-Dweller dive watch. From an ad from 1974: “The Rolex Sea Dweller, however, is fitted with a patented gas escape valve.” Rolex had applied for a patent for this valve on Nov. 6, 1967. “In effect, this means that the watch decompresses with the diver,” explained T. Walker Lloyd, then an oceanographic consultant for Rolex in the same ad. The Sea Dweller then went on to become standard equipment of the Compagnie maritime d’expertises (COMEX) employees (and replacing the previous partnership between Omega and COMEX).

A Diver’s Tool 

Omega and Seiko, however, chose a very different approach to solving the helium problem: instead of improving an existing watch, they both went back to the drawing board. One result was the Seamaster 600 “PloProf” (Plongeur Professionel) from 1970 that was built to be more robust than any other watch from the company before. From an ad from that period: “We also put the 600 through our helium test. Helium, having much smaller molecules, can penetrate where water can’t. So if a watch is proof against helium, it’s proof against just about everything else. This test showed that the 600 is one hundred times as air- and water-tight as the Apollo spacecraft.” Another ad from Omega explained the three major innovations like this: “we carved the Seamaster out of one block of stainless steel; no joints behind. Then we gave it a heavy, hardened mineral glass, which actually screws in. We gave it a turning elapsed-time bezel, which has its own lock to prevent accidental moving. We gave it an extra-safe, twin-locking crown.” Seiko, too, went with a monobloc case construction for its 1975-introduced professional dive watch, the 6159-7010 with a guaranteed water resistance of 600 meters (a watch that was, like the PloProf, in fact much more water resistant than this). The Seiko, however, took seven years to develop and resulted in 20 patents. The 6159-7010 was also built in a way that it could withstand the pressure differences without having to rely on an additional opening in the case, but came with a protective shroud, taking into consideration the heavy underwater work of its customers. On the other hand, both the Seiko and the Omega came with a design, size and price that prevented it from being worn by a large group of consumers, while the Sea-Dweller looked much more like a regular watch both underwater and onshore.

All three models also undoubtedly helped improve the quality of dive watches substantially. In 1966, the British Sub-Aqua Club (BSAC) had set up an investigation committee for diving equipment, including dive watches, which back then were deemed not only “a vital part” of the diver’s equipment, but apparently also the most troublesome. In 1968, BSAC member Geoff Harwood concluded that “the majority of the complaints and allegations of faulty equipment and unsatisfactory dealings with manufacturers and distributors have been concerned with diving watches” — which led to the decision “to carry out a survey in order to determine the extent of the problem.” Harwood’s conclusion was not as encouraging as the industry might have hoped for, “since so few of each make are represented, we cannot draw a conclusion as to ‘best buy’ or to definitely not recommend a certain watch.” And added, “[E]ven if you buy an internationally famous watch costing over £50 you still stand a fair chance of finding it full of water when you come to start your decompression schedule after a deep dive.”

Or, as Robert R. Springer wrote in his Skin & Scuba Diver’s Digest of 1975, “At one time an oddity, today, specially constructed waterproof and pressure-resistant watches have become something of a status symbol among the socalled beautiful people — even though most of them never reach depths greater than the bottom of a martini glass. The practicing scuba diver, however, needs a functional item, rather than an impressive one. And, in looking for an underwater watch, it pays to be highly selective.”

Becoming an Ambassador of the Sea 

In 1983, while the watch industry was slowly starting to recover from its worst crisis to date, the Orca Edge hit the market as the first commercially viable dive computer. Watch brands at that time mostly focused on making dive watches more water resistant (the IWC Ocean 2000 from 1984, for example, was the first serially produced dive watch water resistant to 2,000 meters), and multi-function quartz watches and dive computers quickly started to reduce the mechanical dive watch first to the role of a backup instrument, then mostly a status symbol, as observed by Springer in 1975. In 1990, Seiko launched the “world’s first computerized diver’s watch,” equipped with a water sensor and depth sensor that displayed diving time and depth. Five years before, Citizen had introduced the first Aqualand and also the first quartz watch to incorporate an electronic, digital depth gauge. Despite the existence of a more versatile (and often less expensive) option, dive watches have become one of the most successful categories for luxury watch manufacturers in recent years. The Submariner from Rolex, for example, ranks on positions 2 and 5 on Chrono24’s most popular list from 2020. Even at Breitling, a brand traditionally synonymous with pilots’ watches, the Superocean dive watch has become the brand’s most popular watch category. It’s hard to imagine Tudor’s recent rise to fame without the 2016-introduced Black Bay dive watch, or Rado’s success among watch collectors and enthusiasts without the re-introduced Captain Cook from 2017. Even Seiko has based most of its recent global success on the Prospex dive watch collection. And Panerai, the former supplier of the Italian Navy, was resurrected in 1993 exclusively as a watch brand. Last but not least, since 1995, Omega has been equipping the world’s most famous spy with a Seamaster dive watch, and by doing so has created one of the most recognizable luxury watches of the industry.

But perhaps more importantly, dive watches have become an ambassador for the importance of the oceans. Blancpain, for example, became a force in protecting the biodiversity of the oceans. The 2014-founded Blancpain Ocean Commitment initiative (BOC) is a unique program in the watch industry that has already helped a number of environmental initiatives get off the ground (some of them already underway before BOC was launched). Oris, too, believes “passionately in conservation and is committed to acting sustainably” and has launched several limited edition watches that support various conservation efforts. Others, like Luminox, Breitling and Ulysse Nardin, have started to promote upcycling methods with their releases.

From a quality and performance point of view, today’s mechanical dive watches are better than they have ever been. They have reached the deepest parts of the ocean repeatedly and offer any kind of additional feature one could dream of. In recent years, they have become a symbol of sustainability and preservation, and offer a nostalgic look back at how man conquered the deep at the same time. In other words, the dive watch has stood the test of time and proven that an analog product can coexist with a digital alternative.

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Seiko celebrated its 140th anniversary in 2021 with a number of special models. In addition to a modern reinterpretation of the Prospex Diver’s watch from 1970 created for the adventurer Naomi Uemura, there was also an unlimited edition of the world-famous dive watch, which we put to our test.

In contrast to the limited edition, the unlimited version of this Seiko Prospex model, our test watch, has a roughened matte dial in charcoal gray, much like the original from 1970. By placing the date between 4 and 5 o’clock, 12 bold hour markers can be applied, with a double-bar marker at 12 o’clock, for perfect orientation.

The hour and minute hands, the tip of the second hand, and the indexes are all generously coated with Lumibrite, Seiko’s own luminous material, to ensure optimal nighttime legibility. The orientation point on the dive bezel seems to take a conscious backseat. The unidirectional bezel, which is rendered in the same gray color as the dial, clicks in half-minute increments and is engraved to the exact minute. It encircles a domed crystal with anti-reflective coating on the inside, which contributes to the excellent overall legibility and scratch resistance.

The hard coating on the alternating polished and brushed surfaces of the asymmetrical case, which is widely used on Seiko dive watches, protects against scratches. The recognizable crown screws down inside a nicely shaped, ergonomic crown guard at 4 o’clock. But unscrewing the crown takes a good deal of strength and pulling it to the different setting positions requires a strong fingernail; returning the crown to its screwed-down position also requires some effort. Yet this operation provides a feeling of solid security and water resistance, which the Prospex provides to a depth of 20 bar. The solid threaded caseback adds to this secure feeling. It is engraved with the image of a giant wave — a symbol of the dive watch profession.

The Prospex is also known for its movement, a specially designed caliber for use in professional dive watches. The automatic 8L35 movement is housed beneath the solid caseback. It is derived from the Grand Seiko Caliber 9S55, introduced in 1998 (after a 20-year pause) as the first mechanical watch movement from Grand Seiko. Caliber 8L35 appeared about two years later — specially modified for dive watches by watchmakers in the Shizukuishi Watch Studio Morioka in northern Japan and, like the Grand Seiko movement, assembled and adjusted by hand.

The 8L35 is comprised of 192 components and ticks at a rate of 4 Hz with a power reserve of more than 50 hours. Broadly speaking, this is a less refined version of the Grand Seiko 9S55 caliber with a larger balance wheel to manage the torque needed for advancing the hefty dive watch hands. And, with regard to the rate requirements, we see that the 8L35 is not subject to the same standards as the Grand Seiko caliber. For the accuracy of the 8L35 watch movement, the manufacturer states that the deviation range is +/-15 seconds per day. The movement in our test watch remained within these specifications with deviations between 6 and 7 seconds per day.

The Prospex is worn on a five-row, integrated steel bracelet, with a clasp equipped with a safety bar and a sturdy dive extension. It’s easy to see why this watch has been a professional underwater companion for more than half a century.

The Seiko Prospex Modern Interpretation of 1970 Diver’s Watch retails for $2,900.

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l-r:  Rolex Submariner, Sea-Dweller, and Deepsea models

Rolex currently produces four different dive watch models: the Submariner and Submariner Date, the Sea-Dweller and the Deepsea (listed here in order from lowest to highest in both size and price). The Submariner and Submariner Date share the same case size. Almost all watches in this collection offer versions with different materials, dial and bezel colors. The Submariner without a date indication is the entry-level piece and is priced at $7,500. Introduced in 1953, it was the first dive watch from Rolex. At that time, it had a bidirectional rotating bezel for measuring dive time. Initially, the Submariner was water resistant to 100 meters, but by 1954 Rolex had already increased this level to 200 meters. In 1955, the English Royal Navy began using the Submariner as its official dive watch and the Royal Canadian Navy followed suit the following year.

Rolex first became famous in 1927 for its water-resistant watches with their patented screw-down crown, and the ingenious Oyster name was an effective marketing tool. During her more than 15-hour attempt to swim the English Channel, Mercedes Gleitze wore a water-resistant Rolex that withstood the ordeal. Rolex took out a front-page ad in the London Daily Mail to publicize the event that won the watch great acclaim.

The Submariner with no date indication is the most economically priced Rolex dive watch ($7,500).

Rolex also developed the Deep-Sea Special watch to explore the ocean depths. Between 1953 and 1960 it participated in several maritime expeditions, attached to the outer hull of submarines. The high point (or low point) was reached in 1960 when Jacques Piccard and Don Walsh maneuvered their Trieste submersible vessel down into the Mariana Trench to a depth of 10,916 meters, just a few meters short of the deepest point in the sea. The Deep-Sea Special survived unscathed. Although several pieces of this model were built, it never went into serial production. With a semi-spherical crystal and an overall height of 35 mm, it would still be too large to be considered wearable.

The first Submariner was introduced in 1953.

Submariner
Today’s Submariner measures 40 mm in diameter and 12.5 mm in height, which is slim for a dive watch. The watch without a date indication is powered by the self-winding in-house 3130 movement and with a date, by the 3135. Both calibers boast a power reserve of 48 hours. Chronometer certification from the independent testing agency COSC guarantees accuracy, alongside the company’s own stricter standards, which specify that every Rolex watch may not gain or lose more than 2 seconds per day. The Glidelock system can extend the bracelet for a precise fit and allows the Submariner to be worn over a wet suit. Like all Rolex dive watches, it has a metal bracelet and a unidirectional rotating bezel with a ceramic inlay.

Sea-Dweller
Saturation diving was developed in the early 1960s. When working at deep-sea locations, professional diving companies took advantage of the fact that after 24 hours under pressure, the human body will not absorb additional nitrogen, thereby limiting the time required for decompression. So to prepare themselves for working for extended periods at deep locations, professional divers would spend several days inside a pressure chamber filled with a helium-nitrogen-oxygen mixture. Once their underwater task had been completed, the pressure in the chamber was gradually reduced to normal levels. During this process, crystals from the divers’ watches would often pop out of their cases due to the helium trapped inside the watches. Divers in the Sealab program experienced this problem while helping the U.S. Marines carry out research on the effects of high pressure and various breathing gases on the human body.

The 2017 Sea-Dweller with helium escape valve and Cyclops date ($11,350)

A Sealab diver reported the problem to Rolex and suggested adding a pressure relief valve to safely release the helium that had penetrated the watch. Rolex then developed its helium escape valve, which would be adopted by many other brands.

Rolex began working with the French diving specialist Comex in the early 1970s and supplied watches to all Comex divers, who then shared their experiences and helped with the ongoing development of the watches. Comex laid underwater cables, took care of diving work on oil rigs and salvaged shipwrecks. While doing so, they developed their own special tools and experimented with breathing gas mixtures. Comex set a number of depth records and a Sea-Dweller was on the wrists of their divers as they subjected themselves to each torturous trial. In 1972, two divers withstood 50 hours in a pressurized chamber measured at 610 meters deep. Later, Comex employees worked in the ocean at more than 500 meters, and in 1992, a Comex diver achieved a depth of 701 meters inside a pressure chamber. What Comex really needed was the Sea-Dweller with its three times higher water resistance and a helium escape valve.

The newest Sea-Dweller has been available in a steel-and-gold version since 2019 ($16,050).

In the mid-1960s, Rolex supplied Comex with specially equipped Submariner models to test the helium escape valve. Today, these “Rolex Comex” watches (Ref. 5514) are as expensive as they are rare. The Sea-Dweller went into mass production in 1967, equipped with a helium escape valve. The new model was able to withstand pressure to a depth of 610 meters. It remained similar in design to the Submariner. In 1980, Rolex doubled the Sea-Dweller’s water resistance to 1,220 meters. And to mark the 50th anniversary of the Sea-Dweller in 2017, Rolex issued a new model that replaced the previous model introduced in 2014. With a current diameter of 43 mm and a height of 15 mm, and with the iconic Rolex Cyclops date magnifier, the watch looks much like an enlarged Submariner but with continuous 60-minute markers on the divers’ bezel and red lettering on the dial.

Thanks to a special case, the Deepsea can reach an underwater depth of 3,900 meters (with D-blue dial, $12,550).

Deepsea
The maximum depth limit remained unchanged until 2008, when the Deepsea model was introduced with a water resistance of 3,900 meters. Rolex developed a completely new case design to ensure that the watch would not be too large despite its tremendous water resistance. Its patented “Ringlock” system consists of three elements that can take the pressure: a 5.5-mm-thick sapphire crystal, a 3.28-mm grade 5 titan-ium caseback and an inner ring made of BioDur 108 steel. The system is surrounded by the 904L steel that Rolex uses for the case. The titanium caseback is pressure-fit to the inner ring by a threaded 904L steel caseback ring.

Right: In 1960, the Deep-Sea Special prototype reached a depth of 10,916 meters.

The materials are carefully selected; they exhibit both strength and resilience and do not easily deform or break under pressure. The complicated design permits a 44-mm-by-18-mm case that is both striking and 10-percent thinner than other cases with a similar construction. The Deepsea is designed to withstand depths of up to 4,900 meters. Each individual watch undergoes rigorous underwater testing at this 25-percent higher pressure. The Deepsea was updated in 2018 and now has a more balanced case and a new in-house movement with a power reserve of 70 hours. Like the Sea-Dweller, the Deepsea has a Fliplock extension piece that permits fine incremental extension of the bracelet up to an additional 26 mm.

The year 2012 marked another important underwater project, the “Deepsea Challenge.” And Rolex was a partner once again. The filmmaker James Cameron was the first person to successfully reach what was at that time the deepest point below sea level after the first famous expedition in 1960. Attached to the outside of his submersible vehicle was another specially designed concept watch by Rolex: the Deepsea Challenge, which was water resistant to a depth of 12,000 meters. It relied on the Ringlock system and achieved wearable dimensions of 51.4 mm in diameter and 28.5 mm in height.

Below: In 2012, this prototype reached the deepest point in the ocean at that time.

Variations
With the exception of the Submariner with no date, every Rolex dive watch offers different options. The Deepsea is available with a black dial or with one that transitions from black to blue. As of 2019, the Sea-Dweller is available in both steel and steel-and-gold versions. The steel Submariner is offered with a black or green dial and matching bezel. It is also available in yellow gold and in steel and gold, and with either option the customer can choose a black or blue dial and bezel. A white-gold version is offered with a blue dial and bezel only. All in all, the dive watch collection consists of 12 different versions.

The Submariner with a green bezel and black dial (known as the “Kermit”) and the all-green Submariner (the “Hulk”), priced at $9,050, are highly sought after.

Prices begin at $7,500 for the no-date Submariner, followed by the Submariner Date at $9,050. Models with a helium escape valve are considerably more expensive – the Sea-Dweller is offered at $11,350 and the Deepsea at $12,250. The most expensive model is the white-gold Submariner at $36,850. Despite the limited optical variety of these offerings, there is a suitable divers’ watch from Rolex for every size wrist and almost every wallet.

The most expensive Rolex dive watch is the Submariner Date in white gold ($36,850)..

Rolex and Omega are renowned and admired for their dive watches. In direct comparison, which one of the two leading brands dives deeper, offers more value for the money and performs better?

The Submariner divers’ watch has been one of Rolex’s most popular models, and not only since its redesign in 2020. Omega has also renewed its popular Planet Ocean, Diver 300M and Seamaster 300 collections in recent years. But in what area can one brand overtake the other?

Selection
Rolex only has three dive watches in its lineup: the Submariner, the Sea-Dweller and the Deepsea. If you count the Submariner without date indicator as a separate model, then the total increases to four. In addition, there are only a few variations: the Deepsea is available with two different dials, while the Submariner is available in steel, gold and in a mixture of both, and with dials and bezels in various colors. Rolex’s collection of dive watches has a total of 12 variants. Strap variations or complications beyond time, date and rotating bezel cannot be found in the Rolex dive watch lineup.

Omega offers considerably more choice: the brand’s Dive Watches homepage currently lists 117 variants. The four collections — the Diver 300M, the Seamaster 300, the Planet Ocean and the Ploprof — offer cases in various sizes that are made from different materials, in addition to strap variations, diverse colors and additional functions. In addition to steel cases, there are also titanium cases and even ceramic ones in various colors. Omega also has something to offer in today’s popular retro style with the revised Seamaster 300. Rolex, on the other hand, changes the design of its models very slowly, but still keeps them up to date.

Entry Point
Rolex’s entry-level dive watch, the Submariner without date indicator, sells for $8,100. Omega offers a less costly watch for divers: the Seamaster Diver 300M sells for $4,900 with a rubber strap and $5,200 with a stainless-steel bracelet. Moreover, the demand for the Submariner is so high that it’s difficult to get one from an authorized distributor.

Daily Wearer
The Planet Ocean and the Submariner Date are directly comparable. Both are watches that can be worn every day. While the Omega Planet Ocean starts at $6,200 in steel on a NATO strap, the Rolex Submariner Date costs $9,150 in Oystersteel on an Oyster bracelet, if you are lucky enough to get a chance to buy one. Omega’s model remains water resistant to a depth of 600 meters, while the Rolex makes do with 300 meters. The Omega also includes a helium- release valve and encases manufacture Caliber 8900, which can defy even the strongest magnetic fields, despite having a glass caseback.

Omega offers a significantly better price-performance ratio here. However, Rolex has been using the newer Caliber 3235 in its Submariner Date since 2020, so this model is likely to retain its value better than the Omega, which puts Omega’s initial price advantage in a somewhat different light.

Professional Models
Rolex’s Sea-Dweller and Omega’s Seamaster Ploprof compete with each other in the field of highly pressure-resistant watches. The Omega withstands pressure to a depth of 1,200 meters below the water’s surface; on paper, the Rolex can plunge 20 meters deeper to 1,220 meters (not taking into consideration the additional safety reserves that both watches offer).

The Ploprof costs $9,700 with a steel case and bracelet and $12,600 in titanium. The price for the steel Sea-Dweller is $11,700, which is close to the price of Omega’s titanium model. But Rolex has an ace up its sleeve with the Deepsea, which costs only $900 more at $12,600, yet resists pressure to 3,900 meters. For this purpose, Rolex developed a special case system, in which a ring made of particularly hard, nitrogen-alloyed stainless steel absorbs pressure. This enabled Rolex to create a case that is relatively slim despite its enormous pressure resistance. So when it comes to extreme watches, Rolex defends its leading position (if we’d add the brands’ experimental dive watches, the Seamaster Ultra Deep and the Deepsea Challenge, Omega would win in this category, but we’ll get to these two watches in a minute).

Special Editions
When it comes to special models, Omega can draw on a wealth of resources. This brand has produced numerous limited-edition watches for the Olympics, the sailors of the Emirates Team New Zealand and film super-spy James Bond. Rolex offers the Submariner with a green bezel and the Deepsea with a color gradient on its dial, but these are not limited-edition watches. If you want a rare variation of a Rolex dive watch, you have to buy extremely expensive historical pieces. Omega has more to offer here.

The Movements
Since last year, Rolex has only used two different in-house movements: the 3230 without date for the Submariner and the 3235 for all other dive watches. Both offer 70 hours of power reserve. Omega relies mostly on calibers from the 8000 series and chronograph movements from the 9000 series. These feature Omega’s efficient co-axial escapement and a 60-hour power reserve. Rolex’s calibers have proven to be extremely robust and precise, but Omega’s movements achieved better average rate values in recent tests. Furthermore, Omega went to great lengths to develop comprehensive protection against magnetic fields without a soft iron inner case. Thanks to antimagnetic components in the movement, magnetic fields cannot impair the rate accuracy, so Omega can, and almost always does, install a glass back. Rolex is also constantly improving its movements. Here, both manufacturers are at the same high level, with Omega offering a nicer finish on its movements.

Current Projects
In 2017, Rolex supported the “Under the Pole III” expedition, in which divers explored the ocean beneath the polar ice cap and off the shores of Antarctica. The brand also participated in the Deepsea Challenge in 2012, when filmmaker James Cameron became the first person to reach the deepest point in the sea since the 1960 expedition, which was also supported by Rolex. In 1960 and again in 2012, the exterior of the submersible carried a Rolex concept watch that had been specially developed for this ordeal: the “Deepsea Challenge” is pressure resistant to a depth of 12,000 meters. The developers of this deep diver were able to use the Ringlock system of the Deepsea model and thus achieved wearable dimensions of 51.4 mm in diameter and 28.5 mm in height. As a tribute to this expedition, the Deepsea model was given a “D-blue” gradient dial.

In 2019, Omega followed Rolex’s example and sent a wristwatch into the Mariana Trench. Developed expressly for this purpose, Omega’s Seamaster Planet Ocean Ultra Deep Professional reached a record depth of 10,925 meters on the exterior of the “Limiting Factor” submersible owned by the extreme adventurer Victor Lance Vescovo. Omega built only three pieces of this 55-mm-diameter and 28-mm-tall watch. None of the three is for sale, and all survived the immense pressure intact.

Omega also supports the Nekton Foundation, which is dedicated to protecting the seas, and has created a special model of the Seamaster Diver 300m with a likeness of the Nekton submersible on the caseback. So here both brands are working hard to outdo each other.

James Bond
Author Ian Fleming specified in his novels that secret agent James Bond wears a Rolex. The divers’ watch from the brand appeared on the agent’s wrist in the first seven James Bond films. After an interlude with Seiko’s ultramodern LCD watches, Bond returned to the Submariner in License to Kill (1989). Omega was a partner in the eight 007 films that followed, so various Seamaster dive watches accompanied James Bond. Omega also ran numerous ads to heighten awareness of the brand’s association with James Bond. The secret agent is once again wearing an Omega in the most recent James Bond film No Time to Die. Omega has released two special models to celebrate the film’s debut. Omega is following in Rolex’s footsteps here.

Conclusion
All in all, it’s obvious that each brand has its own specific strengths. Rolex came up with the helium-release valve, Omega with the Ploprof. Rolex sent its watches to the deepest trenches of the ocean’s floor earlier, but Omega has gained ground in recent years,especially with its co-axial movements with built-in protection against magnetic fields. In addition, Omega’s image has been enhanced by the presence of its watches on James Bond’s wrist. While Rolex impresses with the highly pressure-resistant and ingeniously designed Deepsea, Omega offers an enormous variety of dive-watch models.

This article originally appeared in the September-October 2021 issue of WatchTime.